1. Field of the Invention
This invention relates to a biofunctional dental implant having a crown portion connected to a root portion by means of an abutment post. The advancement of the abutment post through a flexible abutment projecting upwardly from the root portion causes the flexible abutment to apply an outward pushing force against the crown portion for holding the crown portion atop the root portion without the use of screws or similar fastening devices.
2. Background Art
Natural teeth in the human mouth are supported in bone by periodontal fibers that function as shock absorbers when a compressive force is applied, such as during chewing. Through disease, accidental injury, anatomical abnormalities, age, and the like, a natural tooth may be removed or missing such that a dental appliance or prosthetic device (e.g., a crown) is implanted in the patient's bone structure to improve the patient's physical appearance and/or quality of mastication. However, problems such as crown breakage, screw loosening and screw breakage are inherent problems with the conventional crown implant.
More particularly, screws commonly associated with conventional crowns sometimes break because of over tightening and due to tension and lateral stress to which the crown is subjected during use. Moreover, a single crown can rotate in response to high lateral and torquing forces that are encountered while chewing, whereby to rotate and loosen screws. As dental professionals will understand, it is difficult and time consuming to retrieve and/or repair such broken screws. In addition, special purpose torque drivers are required to install these screws. Once the root portion of the implant is installed, it may take several months to achieve suitable bone integration of the root portion with the surrounding bone structure thereby resulting in increased loading time before the crown can be reliably attached. What is more, many crowns cannot easily absorb and distribute shock and other physical forces that are generated during chewing. Such crowns may be susceptible to damage or reduced life and may be unable to provide the function of a natural tooth and the quality of mastication associated therewith.
Accordingly, it would be desirable to overcome the problems associated with conventional crowns by avoiding screws which can break or loosen and eliminating the special purpose tools that are needed to install such screws. It would also be desirable to provide the crown with a shock absorbing cushion to better distribute the forces to which the crown will be subjected. It would be further desirable to have a replacement crown which is detachably connected to an existing root portion so that a new crown can be substituted for a defective or broken crown without requiring another surgery as well as the cost and patient discomfort associated therewith.
Reference may be made to my prior U.S. Pat. No. 5,890,902 issued Apr. 6, 1999 and pending patent application Ser. No. 10/159,644 filed Jun. 3, 2002 for examples of dental implants having a crown portion fixedly connected to a root portion.